n-api: stop creating references to primitives

The binding testing napi_wrap() creates references to primitives passed
into the binding in its second parameter. This is unnecessary and not
at all the point of the test. Additionally, creating persistent
references to primitive values may not be supported by all VMs, since
primitives are best persisted in their native form.

Instead, the point of the test is to make sure that the finalize
callback gets called when it should get called, that it gets called
with the correct pointer, and that it does not get called when it
should not get called. Creating persistent references is not necessary
for verifying this.

Re: nodejs/node-chakracore#380

Author: Gabriel Schulhof

doc/api/n-api.md

@@ -786,7 +786,7 @@ NODE_EXTERN napi_status napi_create_reference(napi_env env,
 
 - `[in] env`: The environment that the API is invoked under.
 - `[in] value`: `napi_value` representing the Object to which we want
-a reference to.
+a reference.
 - `[in] initial_refcount`: Initial reference count for the new reference.
 - `[out] result`: `napi_ref` pointing to the new reference.
 

src/node_api.cc

@@ -2458,8 +2458,14 @@ napi_status napi_create_reference(napi_env env,
   CHECK_ARG(env, value);
   CHECK_ARG(env, result);
 
-  v8impl::Reference* reference = v8impl::Reference::New(
-      env, v8impl::V8LocalValueFromJsValue(value), initial_refcount, false);
+  v8::Local<v8::Value> v8_value = v8impl::V8LocalValueFromJsValue(value);
+
+  if (!(v8_value->IsObject() || v8_value->IsFunction())) {
+    return napi_set_last_error(env, napi_object_expected);
+  }
+
+  v8impl::Reference* reference =
+      v8impl::Reference::New(env, v8_value, initial_refcount, false);
 
   *result = reinterpret_cast<napi_ref>(reference);
   return napi_clear_last_error(env);

test/addons-napi/test_general/test.js

@@ -60,7 +60,7 @@ assert.strictEqual(test_general.testNapiTypeof(null), 'null');
 // Ensure that garbage collecting an object with a wrapped native item results
 // in the finalize callback being called.
 let w = {};
-test_general.wrap(w, []);
+test_general.wrap(w);
 w = null;
 global.gc();
 assert.strictEqual(test_general.derefItemWasCalled(), true,
@@ -69,17 +69,17 @@ assert.strictEqual(test_general.derefItemWasCalled(), true,
 
 // Assert that wrapping twice fails.
 const x = {};
-test_general.wrap(x, 25);
+test_general.wrap(x);
 assert.throws(function() {
-  test_general.wrap(x, 'Blah');
+  test_general.wrap(x);
 }, Error);
 
 // Ensure that wrapping, removing the wrap, and then wrapping again works.
 const y = {};
-test_general.wrap(y, -12);
+test_general.wrap(y);
 test_general.removeWrap(y);
 assert.doesNotThrow(function() {
-  test_general.wrap(y, 're-wrap!');
+  test_general.wrap(y);
 }, Error, 'Wrapping twice succeeds if a remove_wrap() separates the instances');
 
 // Ensure that removing a wrap and garbage collecting does not fire the

test/addons-napi/test_general/test_general.c

@@ -142,8 +142,10 @@ static bool deref_item_called = false;
 static void deref_item(napi_env env, void* data, void* hint) {
   (void) hint;
 
+  NAPI_ASSERT_RETURN_VOID(env, data == &deref_item_called,
+    "Finalize callback was called with the correct pointer");
+
   deref_item_called = true;
-  NAPI_CALL_RETURN_VOID(env, napi_delete_reference(env, (napi_ref)data));
 }
 
 napi_value deref_item_was_called(napi_env env, napi_callback_info info) {
@@ -155,15 +157,13 @@ napi_value deref_item_was_called(napi_env env, napi_callback_info info) {
 }
 
 napi_value wrap(napi_env env, napi_callback_info info) {
-  size_t argc = 2;
-  napi_value argv[2];
-  napi_ref payload;
+  size_t argc = 1;
+  napi_value to_wrap;
 
   deref_item_called = false;
 
-  NAPI_CALL(env, napi_get_cb_info(env, info, &argc, argv, NULL, NULL));
-  NAPI_CALL(env, napi_create_reference(env, argv[1], 1, &payload));
-  NAPI_CALL(env, napi_wrap(env, argv[0], payload, deref_item, NULL, NULL));
+  NAPI_CALL(env, napi_get_cb_info(env, info, &argc, &to_wrap, NULL, NULL));
+  NAPI_CALL(env, napi_wrap(env, to_wrap, &deref_item_called, deref_item, NULL, NULL));
 
   return NULL;
 }
@@ -175,9 +175,6 @@ napi_value remove_wrap(napi_env env, napi_callback_info info) {
 
   NAPI_CALL(env, napi_get_cb_info(env, info, &argc, &wrapped, NULL, NULL));
   NAPI_CALL(env, napi_remove_wrap(env, wrapped, &data));
-  if (data != NULL) {
-    NAPI_CALL(env, napi_delete_reference(env, (napi_ref)data));
-  }
 
   return NULL;
 }